Automatic single-needle embroidering machine



Jan. 7, 1930. F. J. Vcam-{LER-r r-:r A1. 1,742,953

AUTOMATIC SINGLE NEEDLE EIBROIDERING IAGHINE Filed Nov. 9. 1926 #H ma vPaz n;

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Patented Jan. 7, 1930i UNITED STATES PATENT OFFICE y AUTOMATICSINGLE-NEEDLE EMBROIDERING MACHINE Application filed November 9, 1926,Serial No. l47,306, and in Germany March 1, 1926.

This invention relates to improvements in the construction of automaticsingle-needle embroidering machines controlled by a jacquard card.

The object of the invention is to provide means for automaticallystopping the automatic single-needle embroidering machines as soon asthe thread gets slack, when the thread breaks or when the embroiderypattern is finished, the same device serving to prevent the restartingof the machine as long as the thread is broken or if nothreads are inthe embroidering tools.

One person attends usually to several automatic single-needleembroidering machines and has to remedy the disturbances which occurduring the embroidering process and which consist mainly of breaking ofthe threads, said attendant having also to stop the machine when theembroidery pattern is finished. It depends therefore entirely on theskill of the attendant Whether more or less great faults occur in theembroidery When the thread breaks. These faults have tobe repaired byhand. The number of machines attended to by one person is limited by thefact that the greater the number of machines to which one person attendsis, the greater will becclne the number of faults in the embroidery, theeconomy of single-needle embroidering machines being further impaired bythis difficulty.

The inconveniences which have just been mentioned are obviated by theinvention or reduced to a minimum, by providing means for automaticallystopping the automatic single-needle embroidering machine at slackeningor breaking of a thread, or when the embroidery pattern is finished, andto prevent re-starting of the machine as long as the thread has not beenthreaded into the needle. The repairing work is, therefore, done awaywith almost entirely, and one person is able to attend to a greaternumber of machines than hitherto, without unfavorable influence upon thequality of the work.

The invention is illustrated in the accompanying drawing.

Referring to the drawing the thread bobbin 67 is rotatably mounted on apin 68 fixed in the machine frame which is not shown in the drawing. Thethread 69 unwound from the bobbin 68 passes through between a pair ofbrake-pulleys 70 Which are fixed on the machine frame. The thread 69 isthen guided around guide bolts 71 and 72, a bolt 7 3 on one end of athread stretching lever 74, a bolt 75 at one end of the thread guidinglever 76, and then through the eye of the embroidering needle 77 to bestitched through the fabric 45. The guide bolts 71 and 72 are fixed onthe machine frame, the thread stretching lever 74, and the threadguiding lever 76 being pivotably mounted on the machine frame at thepoints 78, 79 respectively. The needle 77 is mounted in the machineframe so that it can be shifted in longitudinal direction. The threadstretching lever 7 4 has two arms, a spring 80 attached at one end tothe machine trame being attached at the other end to the free arm ofsaid thread stretching lever 74. This spring 80 serves to pull the freeend of the thread stretching lever against a contact 81 when the threadis not in the needle, this contact `81 being fixed in and insulated fromthe machine frame. At the end 82 of the two-armed thread guiding lever 76 a roller 83 is rotatably mounted which engages with a groove 84 of aneccentric 85 keyed on .the main needle shaft 86. On the main shaft 86 acontrol cam 87 is also keyed which cooperates With a contact spring 88iixed on and insulated from'the machine frame.

The switch of the driving motor 89, which is shown diagrammatically,consists essentially of a switch lever 90, a locking pawl 91, a spring92 connecting said two last men- 'tioned elements, and al contact spring93. The

base plate 94 of the switch-is made from insulating material. Thethree-armed switch lever is pivotally mounted on a pivot axle l 95 of abearing 96. On the bearing 96 a locking pawl 91, composed of three arms,is pivota-bly mounted at 98. The spring 92 the one end of which isattached at 99 to the lever 100 of the switch lever is attached at theother lever 90tending at the same time to make the switch lever pivotinto the cutting-out position this being prevented, when said switchlever is in the switching in position, by a locking nose 104 of thelocking pawl 91. The arm 105 of the switch lever, 90 produces thecircuit closing if it'co'mes into contact with the contact spring 93.This arm has further a knob 106 of insulating material by means of Whichthe switch can be operated by hand. The contact spring is fixed on thebase plate 94 at the point 107. The locking arm 102 of the locking pawl91 has a second locking nose 108 which limits the movement of the switchlever 90 in the cutting-out position so that complete slackening ofspring 92 is thus prevented. The arm 109 ofthe locking pawl 91 servesfor releasing by hand and it has, with this object in view, a knob 110of insulating material. On the arm 111 of the locking pawl 91 a liftingwire 112 is hingedly fixed at the point 113. This lifting Wire 112 isshiftablymounted in a bearing 114 and insulated from the machine frame.The lifting wire 112 is shifted from the jacquard card 57 which lmovesin the direction of the arrow fv. On

the base plate 94 of the switch an electromagnet 115 is mounted thearmature of which is formed by the locking arm 102 of the locking pawl91, 116 and 117 are the two conductors of the net. .118 is the conductorfor the switch lever 90, 1.19 is the conductor leading from the contactspring 93 to the driving motor 89 and 120 is the return conductor to theconductor 116 of the net. The conductor 118, the arm l05'of the switchlever, the contact spring 93,-the conductor 119, the electromotor 89 andthe conductor 1'20 form therefore the circuit for the drivingmotor 89. gThrough the two conductors 121 and 122 the. primary winding 123 of atransformer 124 is further connected to the net conductors 116, 117. Thesecondary winding 125 of the transformer 124 forms, together with aconductor 121, the electromagnet 115, a conductor 127, the contact 81,

the thread stretching lever 74, the mass of t-he machine frame which isnot shown and which is designed to be'represented by the conductor 128shown in dash lines, the cam 87, the contact spring 88 and the conductor129 the so-called releasing circuit.

The operation of-this mechanism is as follows After the. thread 69 whichis wound oil'l the bobbin 67 has been passed over its guide bolts theswitch lever 90 is depressed by hand so that the locking nose 104 ofpawl 91 rips under the locking arm 103 of the switch ever and is held inthis position by the pull exerted by spring 92. By the depresslon of theswitch lever 90 which comes into contact with4 the contact spring 93thecircuit 117,118, 105, 93, 119, 89, 120 and 116 of the electromotor isclosed, so that the electromotor and through it the main shaft 86 arerotated, In

the movements which now begin, owing to the oscillation of the threadguiding lever 76 which is driven by the eccentric 84, 85 and by thedescending and ascending needle 77, the driving mechanism for which isnot shown as it is not necessary for explaining the'present invention,the thread stretching lever 74 is alternately pulled away from thecontact 81 at the moment when the tension of the thread is produced andthen when the thread is subsequently pulled. At the same instant the cam87 acts upon the contact spring 88. If, during the embroidering process,the tension of the thread 69 slackens for any reason or if the threadbreaks, a displacement of the movement of the thread stretching lever 74will take place in the first case, or said thread stretching lever 74will in the second case remain pressed against the contact 81. The mainshaft 86 continuing to rotate the cam 87 will act again upon the contactspring 88 so that this time as the thread stretching lever 74 is pressedagainst the corresponding contact 81, the releasing circuit 125, 126,127, 81, 74, 128, 86, 87, 88 and 129 is closed. The releasingelectromagnet l`115 is thus excited and attracts its armature,consisting of the locking arm 102 of the three-armed locking pawl 91.The locking arm 103 of the switch lever 90 is thus released and pulled,by the action of spring 92, into its position ofrest so that it restsupon the nose 108 of the locking -pawl 91, the arm 105 of the switchlever 90 interrupting the contact with the contact spring 93 whereby thecircuit for the electromotor 89 is interrupted and this electromotor andthe ing previously threa ed the thread into the needle, one presses uponthe knob 106 of the.

switch lever 90, the motor 89 will be started, and the main shaft 86rotated, but the motor will be switched out againl during the firstrotation of shaft 86 by the action of the cam 87 upon the contact spring88,- as the thread stretching lever 74 is still in touch with thecontact 81. When, however, prior to starting the electric motor, thethread 69 is threaded into the needle, the thread stretching lever-74will bemoved away from the contact 81 at the moment when the cam 87 actsupon the contact spring 88 after the electromotor 89 has been switchedin by the depression of the switch lever 90, this oscillation of thethread stretching lever 74 being l caused by the pull exerted by thethread' guiding lever 76, whereby closmg of the releasingl circuit isprevented. The machine will therefore remain running. To stop themachine for any reason whatsoever it is merely necessary t de ress the`knob 110 of the arm 109 of th'e loc ing pawl 91, whereby the sameeffect is produced as described with reference to they electromagneticreleasing. If the embroidery pattern is finished, the jacquard dard 57 Qf the automatic embroider,

not shown on the drawing, pushes against the lifting wire 112 as saidcard has at this point no perforation, and moves periodically at everystitch in the direction of the arrow o towards the lifting wire 112,wherefrom results that the locking pawl 91 is raised and the switchlever 90 pulled back by the action of spring 92 into its cutting-outposition. That this does not occur during the embroidering process isdue to the fact that the jacquard card 57 for the lifting wire 112 hasfor each stitch one hole. a

The above described mechanism stops the machine also at breaking of theshuttlethread, not shown on the drawing, as in K this case the tensionof the thread 69 slackens also. No special thread-detector is required.

We claim A l. In an electrically driven automatic oneneedle embroideringmachine an electromotor, a switch inserted in the circuit of such motor,a shaft driven by the said motor, a cam on the shaft, a threadtensioning arm over which the embroidering thread passes, a locking-member which normally locks the switch of the motor circuit to keep thesaid switch in the closed position, and a release circuit provided withan electromagnet and controlled by the said cam, said electromagnet whenenergized operating to actuate the said locking member so as to causethe switch in the motor circuit to open the motor circuit saidelectromagnet being. inoperative 'until the thread tensioning arm risesupon the slackening of the thread.

2. In an electrically driven' automatic oneneedle embroidering machinean electro-motor, a switch inserted in the circuit of such motor, a.shaft driven by the said motor, a cam on the shaft, a contact springwith which the cam makes contact on rotation of the shaft, a tensioningarm over which the embroidering thread passes, a contact member for sucharm, the said t read tensioning arm and contact forming a closed switchwhen slackening of the thread allows contact between the said arm andContact member, a locking member normally maintaining the theembroidering thread passes, a contact member for such arm, the saidthread tensioning arm and contact member forming a closed` switch whenslackening of the thread allows contact of the said arm and contactmember, a locking member normally maintaining the switch of the motorcircuit closed, an electroof the armature thereof the switch in themotor circuit and thus open the latter when the thread slackens andallows the thread tensioning arm and its contact member ineluded in therelease circuit to make contact. In testimony whereof we have affixedour signatures.

FRANZ JOSEF GAHLERT. MAX BRETSCHNEIDER.

switch of the motor circuit closed, the cam,

contact spring, tensioning arm, contact member, and locking member beingincluded in a release circuit which is closed by the cam on its rotationto operate the locking member to release the switch and thus openthemotor circuit. only when the thread has slackened and allowedcontactbetween the thread tensioning arm and its contact member included in therelease circuit.

3. In an electrically driven automatic oneneedle embroidering machine anelectro-motor, a switch inserted in the circuit of such motor, a shaftdriven by the said motor, a

